Temperature-dependent morphology of chemical vapor grown molybdenum disulfide

Monolayered molybdenum disulfide (MoS₂) is a 2D direct band gap semiconductor with promising potential applications. In this work, we observed the temperature dependency of the morphologies of MoS₂ monolayers from chemical vapor deposition. At a low growing temperature below 850 °C, MoS₂ flakes tend to be trianglular in shape. At 850-950 °C, hexagonal MoS₂ flakes can be observed. While at a temperature over 950 °C, MoS₂ flakes can form rectangular shapes. Complementary characterizations have been made to these samples. We also proposed a mechanism for such temperature-dependent shape evolution based on thermodynamic simulation.